ACT Formula Review

Exponents

100

2³

8

200

2⁵

32

300

3⁴

81

400

13³

2197

500

15³

3375

Volume and Area

100

Area of a rectangle

l*w

200

Area of a Circle

pi r²

300

Area of a parallelogram

h/2(b₁+b₂)

400

Volume of a Pyramid

1/3*B*h

500

Volume of a sphere

4/3*pi*r³

Geometry

100

The acronym to remember the trig functions

SOHCAHTOA

200

The ratios in a 30-60-90 special right triangle

x, x times the square root of 3, and 2x

300

The equation of a circle

(x-h)²+(y-k)²=r²

400

Law of Sines

sinA/a = sinB/b = sinC/c

500

Law of Cosines

b²=a²+c²-2abcosC

Basic Formulas

100

Slope formula

y₂-y₁/x₂-x₁

200

Midpoint Formula

((x₁+x₂)/2,(y₁+y₂)/2)

300

Pythagorean Theorem

a²+b²=c²

400

Distance Formula

The square root of (x₂-x₁)+(y₂-y₁)

500

X-coordinate of the vertex of a parabola

-b/2a

Advanced Formulas

100

Quadratic Formula

-b plus or minus the square root of b²-4ac all over 2a

200

Arithmetic Sequence

n₁+(n-1)d

300

Geometric Sequence

n₁*r^(n-1)

400

Equation of an ellipse

(x-h)²/a² + (y-k)²/b² = 1

500

Combination Formulas

n!/(r!(n-r)!)